doLoad(Widget frmModel,
org.apache.commons.jxpath.JXPathContext jxpc)
Binds the unique-id of the repeated rows, and narrows the context on
objectModelContext and Repeater to the repeated rows before handing
over to the actual binding-children.

void

doSave(Widget frmModel,
org.apache.commons.jxpath.JXPathContext jxpc)
Uses the mapped identity of each row to detect if rows have been
updated, inserted or removed.